A gas turbine engine generally includes a fan and a core arranged in flow communication with one another. The core of the gas turbine engine generally includes, in serial flow order, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, at least a portion of air over the fan is provided to an inlet of the core. Such portion of the air is progressively compressed by the compressor section until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section through the turbine section to drive one or more turbines within the turbine section. The one or more turbines within the turbine section maybe coupled to one or more compressors of the compressor section via respective shaft(s). The combustion gases are then routed through the exhaust section, e.g., to atmosphere.
Gas turbine engines accordingly include a variety of rotating components, which are typically provided with some form of lubrication oil. For example, the gas turbine engines include one or more bearings for supporting rotation of the shaft(s) connecting the turbine section to the compressor section. A bearing sump is provided around the one or more bearings to collect the lubrication oil provided to such one or more bearings.
However, the inventors of the present disclosure have discovered that there is a disparity between a maximum operating range of the one or more bearings (derived as a function of a material hardness of the one or more bearings) and an operating range of the lubrication oil. Accordingly, a gas turbine engine capable of more fully utilizing the maximum operating range of the one or more bearings would be useful. More particularly, a gas turbine engine having an increased efficiency by more fully utilizing the maximum operating range of the one or more bearings would be particularly beneficial.